Viconics VZ8250 User manual

VT8000 Room Controllers
VZ8250 Installation Guide
Variable Air Volume (VAV) Unit
Version 2

TABLE OF CONTENTS
1. SAFETY INFORMATION ................................................................................................................................ 3
2. INSTALLATION .............................................................................................................................................. 6
3. TYPICAL APPLICATION: PRESSURE INDEPENDENT (NO FAN).................................................................. 7
4. TYPICAL APPLICATION: PRESSURE INDEPENDENT (PARALLEL FAN)...................................................... 8
5. TYPICAL APPLICATION: PRESSURE DEPENDENT (NO FAN) ..................................................................... 9
6. TERMINAL IDENTIFICATION ...................................................................................................................... 10
7. HOME SCREEN DISPLAY ........................................................................................................................... 13
8. HOW TO ENTER SET-UP SCREEN.............................................................................................................. 14
9. SET-UP SCREEN DISPLAY .......................................................................................................................... 14
10. BALANCING................................................................................................................................................ 15
APPENDIX A. DEPLOYMENT ......................................................................................................................... 21

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VZ8250 [ Installation Guide ]
1. SAFETY INFORMATION
1.1 IMPORTANT INFORMATION
Read these instructions carefully and look at the equipment to become familiar with the device before trying to install, operate, service
or maintain it. The following special messages may appear throughout this bulletin or on the equipment to warn of potential hazards or
to call attention to information that clarifies or simplifies a procedure.
The addition of either symbol to a “Danger” or “Warning” safety label indicates that an electrical hazard exists which will result
in personal injury if the instructions are not followed.
This is the safety alert symbol. It is used to alert you to potential personal injury hazards. Obey all safety messages that follow
this symbol to avoid possible injury or death.
DANGER
DANGER indicates a hazardous situation which, if not avoided, will result in death or serious injury.
WARNING
WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION
CAUTION indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.
NOTICE
NOTICE is used to address practices not related to physical injury. The safety alert symbol shall not be used with this signal word.
1.2 PLEASE NOTE
Electrical equipment should be installed, operated, serviced, and maintained only by qualified personnel. No responsibility is
assumed by Viconics Technologies for any consequences arising out of the use of this material.
A qualified person is one who has skills and knowledge related to the construction, installation, and operation of electrical equipment
and has received safety training to recognize and avoid the hazards involved.

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1.3 BEFORE YOU BEGIN
LOSS OF CONTROL
WARNING
LOSS OF CONTROL
• The designer of any control scheme must consider the potential failure modes of control paths and, for certain critical control
functions, provide a means to achieve a safe state during and after a path failure. Examples of critical control functions are
emergency stop and over travel stop.
• Separate or redundant control paths must be provided for critical control functions.
• System control paths may include communication links. Consideration must be given to the implications of anticipated
transmission delays or failures of the link.1
• Each implementation of equipment utilizing communication links must be individually and thoroughly tested for proper
operation before being placed into service.
Failure to follow these instructions can result in death, serious injury, or equipment damage.
CALIFORNIA PROPOSITION 65
WARNING
CALIFORNIA PROPOSITION 65
This product can expose you to chemicals including Lead and Bisphenol A (BPA), which are known to the State of California to
cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
Failure to follow these instructions can result in birth defects or other reproductive harm.
ELECTROSTATIC DISCHARGE
NOTICE
STATIC SENSITIVE COMPONENTS
Circuit boards and option cards can be damaged by static electricity. Observe the electrostatic precautions below when handling
controller circuit boards or testing components.
Failure to follow these instructions can result in equipment damage.
Observe the following precautions for handling static-sensitive components:
• Keep static-producing material such as plastic, upholstery, and carpeting out of the immediate work area.
• Store static-sensitive components in protective packaging when they are not installed in the drive.
• When handling a static-sensitive component, wear a conductive wrist strap connected to the component or drive through a
minimum of 1 megohm resistance.
• Avoid touching exposed conductors and components leads with skin or clothing.
1 For additional information about anticipated transmission delays or failures of the link, refer to NEMA ICS 1.1 (latest edition), Safety Guidelines for
the Application , Installation, and Maintenance of Solid State Control or its equivalent

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VZ8250 [ Installation Guide ]
INSTALLATION
NOTICE
INSTALLATION
• The system must be installed correctly by a qualified technician.
• If replacing an existing Room Controller, label wires before removal of Controller.
• Electronic controls are static sensitive devices. Discharge yourself correctly before manipulating and installing Room
Controller.
• A short circuit or wrong wiring may permanently damage Room Controller or equipment.
• All Room Controllers are designed for use as operating controls only and are not safety devices. Tampering with the devices or
unintended application of the devices will result in a void of warranty.
• This device must be installed to provide a separation distance of at least 8in (20cm) from all persons and must not be located
or operating in conjunction with any other antenna or transmitter.
• Refer to the Room Controller User Interface Guide for information on how to configure the Room Controller.
Failure to follow these instructions can result in equipment damage.
LOCATION
NOTICE
LOCATION
• Do not install on an exterior wall.
• Do not install behind a door.
• Do not install in areas with direct heat source.
• Do not install near any air discharge grill.
• Do not install in areas exposed to direct sunlight.
• Ensure Room Controller has sufficient natural air circulation.
• Ensure wall surface is flat and clean.
• Ensure external thermal sensor wirings are away from noisy electrical sources.
• Install 1.3 to 1.5 meter (52 to 60 inches) above the floor.
• Perform preventive maintenance on the damper and Variable Air Volume (VAV) box, according to the supplier documentation.
Failure to follow these instructions can result in equipment damage.
CLEANING THE ROOM CONTROLLER
NOTICE
CLEANING THE ROOM CONTROLLER
• Use a soft, pre-moistened lint-free cloth for cleaning.
• Avoid getting moisture in openings.
• Do not spray anything directly on the Room Controller or use compressed air.
• Do not use caustic/corrosive products, ammonia, solvents or any cleaning product containing alcohol or grit.
• Never use tools directly on the touchscreen.
• Never use paint on the Room Controller.
• Do not drop or crush the Room Controller, or allow it to come into contact with liquids.
• Do not use a damaged device (such as one with a cracked screen).
Failure to comply with these recommendations will result in damage to the unit and void the manufacturer’s warranty.

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Figure-1 Open the cover
Figure-3 Reinstall cover
Figure-2 Install the base
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VZ8250 [ Installation Guide ]
2. INSTALLATION
1. Remove the security screw (if applicable) from the bottom of the
Room Controller cover.
2. Open the unit by pulling on the bottom side of the Room
Controller (Figure 1).
3. Read the FCC ID and IC label installed inside the cover before
installing any wireless product.
4. Ensure the correct side of the base faces up.
5. Pull the cables 6in (15cm) out from wall.
6. Align the base and mark the location of the two mounting holes
on the wall.
7. Install the anchors in the wall (Figure 2).
8. Insert the cable in the central hole of the base.
9. Insert the screws in the mounting holes on each side of the
base.
10. Strip each wire 1/4in (0.6cm) from the end.
11. Insert each wire and screw according to the wiring chart (see
following pages).
12. Gently push excess wiring back into the hole.
13. Gently align the cover with the top of the base and snap it into
place from the bottom (Figure 3).
14. Install the security screw (if applicable).

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3. TYPICAL APPLICATION: PRESSURE INDEPENDENT (NO FAN)
CHANGEOVER
SENSOR
Com.Sens.
SUPPLY AIR
TEMP. SENSOR
OPTIONAL
Com.Sens.
FLOW SENSOR
Com.RCOutput
13 14 15 16 17 18 19 20 21 22 23 24
BACnet + BACnet - BACnet REF UI16 UI17 Common
UI19 - CS
UI20 - RS C (Common) UI22 - SS UI23 UI24 - 0-10V Input
BO1 BO2 BO3
BO4 - Fan On
RC (24VAC)
C (Common)
RH
BO8 - Aux Heat
UO9 - Close Damp.
UO10 - Open Valve
UO11 - 0-10V Output UO12 - 0-10V Output
0-10V Analog Control
7 8 9 10 11 121 2 3 4 5 6
Spacer
BASEBOARD 24V~
24V Com.
0-10V ANALOG
HEATING COIL
Com.InputRC InputRC
0-10V ANALOG ACTUATOR
DAMPER
Com.
COMMON
24 VAC
FAN HI
FAN MED
FAN LO
Low-voltage
TERMINAL BLOCK
Configuration Parameter Name Configuration Settings
VAV box type PI
Actuator type 0-10V DA
Fan type None
Reheat conguration Duct + baseboard
Duct heater 0-10V DA
Baseboard conguration PWM VAC
Refer to the VZ8250 Application Guide for more information on the “Sequence of Operations and Wiring”.

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4. TYPICAL APPLICATION: PRESSURE INDEPENDENT (PARALLEL FAN)
0-10V Analog Control + Parallel Fan
BO1 BO2 BO3
BO4 - Fan On
RC (24VAC)
C (Common)
RH
BO8 - Aux Heat
UO9 - Close Damp.
UO10 - Open Valve
UO11 - 0-10V Output UO12 - 0-10V Output
7 8 9 10 11 12
Spacer
CHANGEOVER
SENSOR
Com.Sens.
SUPPLY AIR
TEMP. SENSOR
OPTIONAL
Com.Sens.
FLOW SENSOR
Com.RCOutput
13 14 15 16 17 18 19 20 21 22 23 24
BACnet + BACnet - BACnet REF UI16 UI17 Common
UI19 - CS
UI20 - RS C (Common) UI22 - SS UI23 UI24 - 0-10V Input
0-10V ANALOG
HEATING COIL BASEBOARD 24V~
24V Com.Com.InputRC InputRC
0-10V ANALOG ACTUATOR
DAMPER
Com.
COMMON
24 VAC
FAN HI
FAN MED
FAN LO
Low-voltage
TERMINAL BLOCK
PARALLEL
FAN
Com.Enable
1 2 3 4 5 6
Configuration Parameter Name Configuration Settings
VAV box type PI
Actuator type 0-10V DA
Fan type Parallel binary
Reheat conguration Duct + baseboard
Duct heater 0-10V DA
Baseboard conguration PWM VAC
Refer to the VZ8250 Application Guide for more information on the “Sequence of Operations and Wiring”.

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5. TYPICAL APPLICATION: PRESSURE DEPENDENT (NO FAN)
BO1 BO2 BO3
BO4 - Fan On
RC (24VAC)
C (Common)
RH
BO8 - Aux Heat
UO9 - Close Damp.
UO10 - Open Valve
UO11 - Open Damp.
UO12 - Close Valve
Floating Control
7 8 9 10 11 12
Spacer
CHANGEOVER
SENSOR
Com.Sens.
SUPPLY AIR
TEMP. SENSOR
OPTIONAL
Com.Sens.
COMMON
24 VAC
FAN HI
FAN MED
FAN LO
Low-voltage
TERMINAL BLOCK
13 14 15 16 17 18 19 20 21 22 23 24
BACnet + BACnet - BACnet REF UI16 UI17 Common
UI19 - CS
UI20 - RS C (Common) UI22 - SS UI23 UI24 - 0-10V Input
1 2 3 4 5 6
BASEBOARD 24V~
24V Com.
HEATING VALVE
Com.OpenClose OpenClose
FLOATING ACTUATOR
DAMPER
Com.
Configuration Parameter Name Configuration Settings
VAV box type PD
Actuator type Floating
Fan type None
Reheat conguration Duct + baseboard
Duct heater Floating
Baseboard conguration Valve NC (Normally Closed)
Refer to the VZ8250 Application Guide for more information on the “Sequence of Operations and Wiring”.

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6. TERMINAL IDENTIFICATION
6.1 FAN TYPE
Supported fan types:
• Parallel On/Off
• Serial On/Off
• Parallel ECM
• Serial ECM
Supported output types:
• On/Off: Binary Output
• ECM: Analog Output
Binary (24V~)
Terminal Name Connection
4BO4 24V~ Enable
6, 18 or 21 C / 24 V~ Common 24 V~ Common
ECM (0-10V DC)*
Terminal Name Connection
6, 18 or 21 C / 24 V~ Common 24 V~ Common
10 UO10 0-10V Output
* Warning! Floating duct reheat is not possible when Fan Type is ECM.
6.2 AIR FLOW SENSOR (PI ONLY)
Supported air flow sensor parameters:
• Output voltage = 0-10V (DC)
• Pressure range = 0.5 or 5 inch water column
• Flow a 1 inch water column:
Minimum = 10
Maximum = 10000
NOTE: Refer to the VAV box manufacturer flow chart for the recommended settings.
Recommended air flow sensor: Schneider Electric (Veris) PX3PXX01 or equivalent.
PI-Only Air Flow Sensor
Terminal Name Connection
5RC / 24 V~ Hot 24 V~ Hot
6, 18 or 21 C / 24 V~ Common 24 V~ Common
24 UI24 0-10V Input

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6.3 DAMPER
Supported output types:
• 0-10V Direct Acting
• 0-10V Reverse Acting
• 2-10V Direct Acting
• 2-10V Reverse Acting
• Floating
Recommended damper: Schneider Electric MS41-6043 or equivalent.
0-10V Analog Actuator
Terminal Name Connection
5RC / 24 V~ Hot 24 V~ Hot
6, 18 or 21 C / 24 V~ Common 24 V~ Common
11 UO11 0-10V Output
Floating Actuator*
Terminal Name Connection
6, 18 or 21 C / 24 V~ Common 24 V~ Common
9UO9 Close Actuator
11 UO11 Open Actuator
* Floating actuation time limits:
Minimum = 0.5 minutes
Maximum = 9.0 minutes
Increment = 0.5 minutes
6.4 CHANGEOVER & SUPPLY SENSORS
The Room Controller is compatible with remote mount temperature sensors using 10k type 2 NTC thermistors.
Changeover & Supply Sensors
Terminal Name Connection
19 UI19 Changeover Sensor
6, 18 or 21 C / 24 V~ Common 24 V~ Common
22 UI22 Supply Sensor

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6.5 REHEAT - DUCT
Supported output types:
• 0-10V Direct Acting
• 0-10V Reverse Acting
• 2-10V Direct Acting
• 2-10V Reverse Acting
• Floating
• On/Off
• PWM
• Valve NC
• Valve NO
0-10V Analog Duct Heater
Terminal Name Connection Required Settings
5RC / 24 V~ Hot 24 V~ Hot Duct Heater Conguration:
• 0-10V Direct Acting, or
• 0-10V Reserve Acting
6, 18 or 21 C / 24 V~ Common 24 V~ Common
12 UO12 0-10V Output
Floating Duct Heater
Terminal Name Connection Required Settings
6, 18 or 21 C / 24 V~ Common 24 V~ Common
Duct Heater Conguration:
Floating
10 UO10 24 V~ Open Damper Actuator
12 UO12 24 V~ Close Damper Actuator
On/Off or PWM Duct Heater
Terminal Name Connection Required Settings
6, 18 or 21 C / 24 V~ Common 24 V~ Common Duct Heater Conguration:
• On/Off, or
• PWM, or
• Valve NC, or
• Valve NO
12 UO12 24 V~ Output
6.6 REHEAT - BASEBOARD
The VZ8250 controls baseboard heaters via:
• Relay = 4 CPH (Cycles Per Hour)
• PWM = 10-second duty cycle
• Valve (Normally Open or Normally Closed) = 8 CPH (Cycles Per Hour)
Supported output types:
• Relay On/Off
• PWM
• Valve NC
• Valve NO
Relay with Transformer (Dry Contact)
Terminal Name Connection Required Settings
7RH Room Controller Terminal 5 (24 V~) Baseboard Reheat: Relay
8BO8 24 V~ to Baseboard
24V~
Terminal Name Connection Required Settings
5RC / 24 V~ Hot Room Controller Terminal 7 (RH) Baseboard Reheat:
• Relay, or
• PWM, or
• Valve NC, or
• Valve NO
6, 18 or 21 C / 24 V~ Common 24 V~ Common
7RH Room Controller Terminal 5 (24 V~)
8BO8 24 V~ to Baseboard

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7. HOME SCREEN DISPLAY
Date Time
Occupancy Status System Status
Up Arrow
Raise Temperature Setpoint
Actual Setpoint
Room Indoor Temperature
Room Indoor Humidity
Outdoor Temperature
Down Arrow
Lower Temperature Setpoint
Unoccupied Mode Override
Help
Enter help screen
Language
Select preferred language
Hospitality User Interface Shown

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8. HOW TO ENTER SET-UP SCREEN
Touch and hold this point
for 3 seconds to enter set-up mode
NOTE: If a configuration/installer
password is activated to prevent
unauthorised access to the
configuration menu parameters,
a password entry prompt shows
to prevent access to device
configuration components.
For more information on using and
configuring the functions of the
HMI, refer to the
VZ8250 User Interface Guide
9. SET-UP SCREEN DISPLAY
Return to
home screen
1/2 Setup
Network
Configuration
Balancing
Setpoints
Display
Service View
General Note:
Adjustable parameter
Nonadjustable parameter
Enter BACnet® & ZigBee® network settings
Enter parameter conguration menu
Enter balancing settings
Enter display settings
Enter setpoint settings
Enter status and service view
For more information on using and configuring the functions of the HMI, refer to the VZ8250 User Interface Guide.

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10. BALANCING
During balancing, a technician will install a calibrated flow sensor (Balometer) over the outlet in each room and use this to calibrate the
VZ8250:
• Pressure Independent:
True air flow will be measured and compared to the airflow calculated by the VZ8250 at various setpoints.
VZ8250 calibration parameters will be adjusted by the technician to ensure the calculated air flow matches the true air flow.
• Pressure Dependent:
True air flow at various damper percentages will be measured and used to set the appropriate damper percentages for the
air flow required for the zone.
Flow sensor
(PI only)
Damper
Calibrated
Flow Sensor
(Balometer)
NOTE: Balancing menus will timeout after 8 hours and any Damper Override will be removed, returning the zone to normal operation.
10.1 PRESSURE INDEPENDENT
Before starting to Balance the system, check the following parameters are correctly configured in the Configuration menu:
• VAV Box Type
• Flow at 1-inch water column
• Airflow Sensor Pressure Range
• Actuator Type
• Floating Actuator Time
Airflow Balancing settings can be found on the Balancing page of the Setup menu.

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The recommended process for Balancing the system is:
1. On page “1/2 Balancing (PI)”, check the Minimum, Maximum Cooling, Maximum Heating and Reheat airflow setpoints are
correctly configured for the zone.
2. Check airflow sensor is correctly zeroed:
a. On page “2/2 Balancing (PI)”, set Damper Override to Close.
b. Wait for measured “Airflow level” to stabilize and confirm the value is less than the desired Minimum Airflow. If not, confirm
damper is closed and auto-zero the airflow sensor. Refer to the flow sensor Installation Guide for more information on
zeroing.
3. Before setting the Minimum and Maximum Cooling airflow, make sure that when fully open, the airflow is at least 40-60 CFM
higher than the planned Maximum Cooling airflow. Otherwise, the control will be erratic.
NOTICE
MINIMUM AND MAXIMUM COOLING AIRFLOW
When damper is fully open, the airflow must be at least 40-60 CFM higher than the planned Maximum Cooling airflow.
Failure to follow these instructions can result in erratic airflow control depending on the HVAC design.
4. Calibrate sensor at Minimum airflow:
a. On page “2/2 Balancing (PI)”, set the Damper Override to Minimum Flow. The displayed Airflow Setpoint will use the value
of Minimum Airflow.
b. Wait for the Room Controller measured “Airflow level” to stabilize.
c. Take a reading of the actual airflow using a calibrated Balometer.
d. Enter the actual airflow as the “Balometer” value on “2/2 Balancing (PI)”. The Room Controller will calculate and display a
new Minimum Flow Offset.
e. Wait for the measured “Airflow level” to stabilize again. The Airflow level should now match the Airflow setpoint. Repeat if
necessary.
5. Calibrate sensor at Maximum Cooling airflow:
a. On page “2/2 Balancing (PI)”, set the Damper Override to Maximum Cooling. The displayed Airflow Setpoint will use the
value of Maximum Cooling Airflow.
b. Wait for Room Controller measured “Airflow level” to stabilize.
c. Take reading of actual airflow using a calibrated Balometer.
d. Enter the actual airflow as the “Balometer” value on “2/2 Balancing (PI)”.
e. The Room Controller will calculate and display a new Maximum Flow Offset.
f. Wait for the measured “Airflow level” to stabilize again. Airflow level should now match the Airflow setpoint. Repeat if
necessary.
6. On page “2/2 Balancing”, revert the Damper Override to None allowing the system to return to normal operation.

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BALANCING OPTIONS
Airflow level
1/2 Balancing (PI)
50 CFM
180 CFM
Max. cool flow
50 CFM
Min. flow
180 CFM
Max. heat flow
80 CFM
Reheat flow
49 CFM
Airflow setpoint
Pressure Independent
Configuration parameter BACnet Function description
Airflow Level AHV110 (R) Measured (calibrated) airow:
• Units = CFM
• Min = 0
• Max = 20000
Airflow Setpoint AI350 (R) Measured (calibrated) airow:
• Units = CFM
• Min = 0
• Max = 10000
Minimum Airflow AV250 (R/W) Minimum airow supplied to the zone:
• Units = CFM
• Min = 0
• Max = 10000
• Default = 50
Maximum Cooling Airflow AV252 (R/W) Maximum airow supplied to the zone when cooling:
• Units = CFM
• Min = 0
• Max = 10000
• Default = 200
Maximum Heating Airflow AV251 (R/ W) Maximum airow supplied to the zone when heating:
• Units = CFM
• Min = 0
• Max = 10000
• Default = 200
Maximum Reheat Airflow AV253 (R/W) Maximum airow supplied to the zone with duct reheat:
• Units = CFM
• Min = 0
• Max = 10000
• Default = 50

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Airflow level
2/2 Balancing (PI)
50 CFM
50 CFM
Balometer
Min. flow
Damp. override
-5 CFM
Min. flow offset
49 CFM
Airflow setpoint
Pressure Independent
Configuration parameter BACnet Function description
Airflow Level AHV110 (R) Measured (calibrated) airow:
• Units = CFM
• Min = 0
• Max = 20000
Airflow Setpoint AI350 (R) Measured (calibrated) airow:
• Units = CFM
• Min = 0
• Max = 10000
Damper Override
Force damper to selected
position during balancing
MV172 (R/ W) 0None (Default)
No damper override. Damper under normal control.
1Min. flow
Force damper to maintain minimum airow setpoint
2Max. cool
Force damper to maintain maximum cooling airow setpoint
3Close
Force damper closed
4Reheat
Force damper to maintain maximum reheat airow setpoint
5Open
Force damper fully open
Balometer
Measured value will be used to
update calibration Offset and
ensure measured Airow level
matches Balometer reading.
Measured airow from Balometer:
• Units = CFM
• Min = 0
• Max = 20000
Minimum Airflow Offset
Calibration offset applied to
Airow Level at Minimum ow
AV258 Measured airow from Balometer:
• Units = CFM
• Min = 0
• Max = 20000
• Default = 0
Maximum Airflow Offset
Calibration offset applied to
Airow Level at Maximum ow
AV259 Measured airow from Balometer:
• Units = CFM
• Min = -5000
• Max = 5000
• Default = 0

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VZ8250 [ Installation Guide ]
10.2 PRESSURE DEPENDENT
Before starting to Balance the system, check the following parameters are correctly configured in the Configuration menu:
• VAV Box Type
• Actuator Type
• Floating Actuator Time
Air Flow Balancing settings can be found on the Balancing page of the Setup menu.
The recommended process for Balancing the system is:
1. On page “Balancing (PD)”, set the approximate damper positions for Minimum, Maximum Cooling, Maximum Heating, Maximum
Reheat.
2. For each position, repeat the following process:
a. Set the Damper Override to the desired position (Minimum, Maximum Cooling, Maximum Heating or Maximum Reheat).
b. Allow time for damper to reach defined position.
c. Take reading of actual air flow using a calibrated Balometer.
d. Compare actual airflow to desired airflow and adjust the Damper Position accordingly.
e. Repeat until measured airflow at the damper position matches the desired airflow.
3. On page “Balancing (PD)”,”, revert the Damper Override to None to allow the system to return to normal operation.
BALANCING OPTIONS
Min. position
Balancing
100 %
30 %
Reheat pos.
100 %
Max. heat pos.
None
Damp. override
10 %
Max. cool pos.
Pressure Independent
Configuration parameter BACnet Function description
Minimum Position AV250 (R/W) Minimum damper position:
• Units = %
• Min = 0
• Max = 100
Maximum Cooling Position AV251 (R/ W) Maximum damper position during cooling:
• Units = %
• Min = 0
• Max = 100

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Pressure Independent
Configuration parameter BACnet Function description
Maximum Heating Position AV252 (R/W) Maximum damper position during heating:
• Units = %
• Min = 0
• Max = 100
Reheat Position AV253 (R/W) Damper position during reheating:
• Units = %
• Min = 0
• Max = 100
Damper Override
Force damper to selected
position during balancing
MV172 (R/ W) 0None (Default)
No damper override. Damper under normal control.
1Min. flow
Force damper to maintain minimum airow setpoint
2Max. cool
Force damper to maintain maximum cooling airow setpoint
3Close
Force damper closed
4Reheat
Force damper to maintain maximum reheat airow setpoint
5Open
Force damper fully open